#include <boost/thread/thread.hpp>
#include <boost/thread/shared_mutex.hpp>

#include <iostream>

boost::shared_mutex mutex;

void thread()
{
    try
    {
        for (;;)
        {
            boost::system_time timeout = boost::get_system_time() + boost::posix_time::milliseconds(50);

            if (mutex.timed_lock(timeout))
            {
                boost::this_thread::sleep(boost::posix_time::milliseconds(10));
                mutex.unlock();
            }
        }
    }
    catch (boost::lock_error& le)
    {
        std::cerr << "lock_error exception\n";
    }
}

int main()
{
    const int nrThreads = 20;
    boost::thread* threads[nrThreads];

    for (int i = 0; i < nrThreads; ++i)
        threads[i] = new boost::thread(&thread);

    for (int i = 0; i < nrThreads; ++i)
    {
        threads[i]->join();
        delete threads[i];
    }
    return 0;
}